Common names: EIA-449, RS-449, ISO 4902
Secondary (auxilary) channel
 (at the Computer)
 (at the Computer)
| Pin | Name | RS232 | V.24 | Dir | Description | 
|---|---|---|---|---|---|
| 1 | n/a | 101 |  | Shield | |
| 2 | SSR | SRR | 122 |  | Secondary Receiver Ready | 
| 3 | SSD | SSD | 118 |  | Secondary Send Data | 
| 4 | SRD | SRD | 119 |  | Secondary Receive Data | 
| 5 | SG | SG | 102 |  | Signal Ground | 
| 6 | RC | RC | 102b |  | Receive Common | 
| 7 | SRS | SRS | 120 |  | Secondary Request To Send | 
| 8 | SCS | SCS | 121 |  | Secondary Clear To Send | 
| 9 | SC | SC | 102a |  | Send Common | 
  Note: Direction is DTE (Computer) relative DCE (Modem).
  Note: RS232 column is RS232 circuit name.
  Note: V.24 column is ITU-TSS V.24 circuit name.
Contributor: Joakim Ögren
| Source: | RS449 Page at Connectivity Knowledge Platform (Made IT) | 
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  May be copied and redistributed, partially or in whole, as appropriate.
  Document last modified: 2002-01-10